1. Field of Invention
This invention pertains generally to internal combustion engines and, more particularly, to a rotary valve system and an internal combustion engine utilizing the same.
2. Related Art
Although widely used in automotive engines and other internal combustion engines, conventional poppet valves have a number of limitations and disadvantages. With the strong springs required to close them and hold them shut and the camshafts, rockerarms, and/or other mechanism required to open them, standard valve trains can require a significant portion of an engine's output to operate them.
Since poppet valves usually extend into the firing chambers when open, they can limit the minimum chamber volume and thus prevent an engine from having maximum volumetric efficiency, and measures must be taken to ensure that the valves do not collide with the pistons. Valve float can also be a problem, and if a valve ever does get sucked into a cylinder, it can destroy the engine. Poppet valves may require periodic adjustment, and typically have relatively large heads which can obstruct the flow of both the fuel mixture and the exhaust gases. In addition, it is very difficult to vary the valve timing with poppet valves.
Heretofore, there have been attempts to use rotary valves and electronically controlled valves instead of poppet valves in internal combustion engines. However, they also have had limitations and disadvantages which have limited their usefulness.